Multiply any 4 digit numbers

So, far, we have already learnt the shortcuts, how to multiply of any 2-digit and 3-digit number using criss-cross multiplication technique. In this tutorial, we will see how to multiply any 4 digit numbers.

Now Let’s try to understand the criss-cross multiplication technique to multiply any 4 digit numbers. As you know, the number of steps  when multiplying any 4-digit numbers  is 7.

Let us consider a simple example 3215 x 4231.

The step-by-step procedure can be explained with the following figure:

 

criss-cross_41

Notice the carry-forward in each stage of the multiplication.  I hope, The steps are self – explanatory.  Notice the additional steps compared to 2 x 2 and 3 x 3 multiplication.

Exercise : On the similar lines, can you multiply?

  • 2318×1339
  • 7222×4223
  • 9222×9229
  • 5216×1265

Multiplication when the number of digits are unequal

If the number of digits in multiplicand and multiplicand is unequal, you add zeros so that the digits have the same number of digits.

 

Let us consider an example. Suppose you have to multiply 4125 x 511. So, the number of digits are 4 and 3 respectively.

So, we convert 511 to 05111 and use this technique.

The multiplication steps are illustrated in the following figure :

 

criss-cross_42

 

Exercise : Can you multiply?

  • 12 x 145
  • 222 x 4223
  • 92 x 9
  • 52 x 125

If you have any doubts using this shortcut, please leave a comment or contact me. I would be glad to help.

Kiran Chandrashekhar

Hey, Thanks for dropping by. My name is Kiran Chandrashekhar. I am a full-time software freelancer. I love Maths and Mathematical Shortcuts. Numbers fascinate me. I will be posting articles on Mathematical Shortcuts, Software Tips, Programming Tips in this website. I love teaching students preparing for various competitive examinations. Read my complete story.

18 Comments

  1. Hello there, just became aware of your blog thorguh Google, and found that it is truly informative. I’m going to watch out for brussels. I will appreciate if you continue this in future. Many people will be benefited from your writing. Cheers!

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  3. hi sir ur blog is informative thanku verymuch.mathematics is like a nightmare for me u made it so easy for me.keep posting.I dont know any shortcut methods and am preparing forRRB TC posts.clarify my doubts if possible

    • Thanks a lot for your nice words. Write to me with your specific questions, I shall try to answer it.

  4. Hello Kiran, I was searching for math shortcuts for SBI clerk exams whn i came accross ur site.And let me tell u,it was incredibly helpful!I hv already bookmarked it.pls post some shortcuts for decimal multiplication as well.Thanks! 🙂

  5. Hello Kiran, I was searching for math shortcuts for SBI clerk exams whn i came accross ur site.And let me tell u,it was incredibly helpful!Thank u so much for dis indispensable service! U are simply brilliant.I hv already bookmarked it.pls post some shortcuts for decimal multiplication as well.Keep going.:)

  6. sir, i have a query.
    i found some problem in adding..
    for example 2485 x 9483

    4 step of calculation is – 45+6+32+32=115

    so my question is with how many digit we should proceed to further calculation…plzz tell…

  7. very useful thanks sir…. can give shortcuts for (2to3), (2to4), (3to4) digits etc…

  8. Hi Mr. Chandrashekhar,
    Thanks for the steps in doing the four digit multiplications. I hope you didn’t mind but I copied the steps so I can have a guide close to me. And again thanks.

  9. Thanks sir this technique is very helpful………..it made calculations very easy………

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